Stem cells can turn into any cell of the body, so scientists are interested in using them to create tissue for treating disease. Brain tissue might be used to treat Parkinson’s, for example. A decade ago, researchers proposed creating tissue from stem cells that bear the patient’s DNA, obtained with
cloning.

If DNA from a patient is put into a human egg, which is then grown into an early embryo, the stem cells from that embryo would provide a virtual genetic match. So in theory, tissues created from them would not be rejected by the patient.

That idea was met with ethical objections because harvesting the stem cells involved destroying human embryos.

Scientists have tried to get stem cells from cloned human embryos for about a decade, but have failed. Generally, the embryos stopped developing before producing the cells.

In Wednesday’s edition of the journal Cell, however, scientists in Oregon report harvesting stem cells from six embryos created from donated eggs. Two embryos had been given DNA from skin cells of a child with a genetic disorder, and the others had DNA from fetal skin cells.

George Daley, a stem cell specialist at Children’s Hospital Boston who did not participate in the work, called results “one landmark step in a very long journey” toward creating DNA-matched tissue. Now, Daley said, scientists must compare this approach with another that reprograms blood or skin cells directly into substitutes for embryonic stem cells.